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package service;

import entities.Project;
import java.util.Collection;
import javax.ws.rs.Path;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Produces;
import javax.ws.rs.Consumes;
import javax.ws.rs.PathParam;
import javax.ws.rs.QueryParam;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.UriInfo;
import javax.persistence.EntityManager;
import entities.ProjColumn;
import converter.ProjectsConverter;
import converter.ProjectConverter;
import javax.persistence.PersistenceContext;
import javax.ejb.Stateless;

/**
 *
 * @author Alex
 */

@Path("/projects/")
@Stateless
public class ProjectsResource {
    @javax.ejb.EJB
    private ProjectResource projectResource;
    @Context
    protected UriInfo uriInfo;
    @PersistenceContext(unitName = "uTaskPU")
    protected EntityManager em;
  
    /** Creates a new instance of ProjectsResource */
    public ProjectsResource() {
    }

    /**
     * Get method for retrieving a collection of Project instance in XML format.
     *
     * @return an instance of ProjectsConverter
     */
    @GET
    @Produces({"application/xml", "application/json"})
    public ProjectsConverter get(@QueryParam("start")
                                 @DefaultValue("0")
    int start, @QueryParam("max")
               @DefaultValue("10")
    int max, @QueryParam("expandLevel")
             @DefaultValue("1")
    int expandLevel, @QueryParam("query")
                     @DefaultValue("SELECT e FROM Project e")
    String query) {
        return new ProjectsConverter(getEntities(start, max, query), uriInfo.getAbsolutePath(), expandLevel);
    }

    /**
     * Post method for creating an instance of Project using XML as the input format.
     *
     * @param data an ProjectConverter entity that is deserialized from an XML stream
     * @return an instance of ProjectConverter
     */
    @POST
    @Consumes({"application/xml", "application/json"})
    public Response post(ProjectConverter data) {
        Project entity = data.resolveEntity(em);
        createEntity(data.resolveEntity(em));
        return Response.created(uriInfo.getAbsolutePath().resolve(entity.getProjId() + "/")).build();
    }
    
    /**
     * Returns a dynamic instance of ProjectResource used for entity navigation.
     *
     * @return an instance of ProjectResource
     */
    @Path("{projId}/")
    public ProjectResource getProjectResource(@PathParam("projId")
    Long id) {
        projectResource.setId(id);
        projectResource.setEm(em);
        return projectResource;
    }

    /**
     * Returns all the entities associated with this resource.
     *
     * @return a collection of Project instances
     */
    protected Collection<Project> getEntities(int start, int max, String query) {
        return em.createQuery(query).setFirstResult(start).setMaxResults(max).getResultList();
    }

    /**
     * Persist the given entity.
     *
     * @param entity the entity to persist
     */
    protected void createEntity(Project entity) {
        em.persist(entity);
        for (ProjColumn value : entity.getProjColumnList()) {
            Project oldEntity = value.getProjId();
            value.setProjId(entity);
            if (oldEntity != null) {
                oldEntity.getProjColumnList().remove(value);
            }
        }
    }
}
